Automatic dishwashers and washing machines typically require a float and switch arrangement for controlling water levels. Electrically operated timing devices are also used to control water levels in appliances.
A problem encountered with the above-described prior art control devices has been failure of the switch associated with the control arrangement resulting in an overflow or flood condition which could only be prevented if the operator were on hand to cut off the appliance power supply.
A further problem encountered with prior art devices has been that heretofore it was difficult to control the accuracy and repeatability of the water levels which was, in part, due to an accumulation of broad manufacturing tolerances inherent in low-cost timing devices and float arrangements.